I have the 30.8 and I would be shocked if the 30.5 couldn’t completely drive the heck out of those KEF’s. You will never see a more power-underrated amp than these Pass Class A’s. Those speakers are 8 ohm and only dip down 4.2 ohms. The Pass amp can drive 4 ohm speakers with authority. John Atkinson’s measurements showed that it could deliver 195 watts per channel into a 4 ohm load before clipping. And overall it delivers 6dB higher in power. The sound won’t be as magical as say paired with a 90dB speaker (like what I use) but it will get the job done and then some IMO.
https://www.stereophile.com/content/pass-labs-xa305-power-amplifier-measurements
https://www.stereophile.com/content/pass-labs-xa305-power-amplifier-measurements